It's an earlier version of Lala's map (which I still had laying somewhere, I never throw anything) with a different tileset we used to quickly build the joke game. There's a lot of reused / revamped / rescued from ditched material stuff in the multicart.

The original map was quite horrible, with lots of spots where rooms were connected very awkwardly. That's why I redid many sections for Lala. When my pal told me about doing a joke game about Sonic I just threw in the old version of the map.